These Holley In-Tank Electric Fuel Pumps utilize a proven factory type gerotor design that is rated for continuous service. The addition of a high output fuel pump is an absolute necessity when other engine modifications such as camshaft, headers, larger injectors, fuel rails and higher flow throttle bodies, etc. are being contemplated. The outside dimensions, however, are compact enough to fit existing hanger assemblies, without modification. These are complete kits and include all parts, accessories and installation instructions along with an inlet filter for improved filtration and durability